Yeah, I've been researching beam weapons myself, but the AI hasn't been having any magical accuracy problems with mass drivers that I've seen, they hit just fine.
Mass drivers do have terrible stats, you can do twice as much with missile weapons, but this is ignoring defenses. You can also buy twice as much ECM to match it. Armor has pretty good stats, but only against diverse damage, if you're just running mass drivers, they'll be forced to put half of their defensive points into types not being utilized.
Weapons may need some balance work, but they're balanced against the corresponding defensive options, not just each other.